1. Field of the Invention
Up to date, the importance of ions is recognized in various fields such as health fields, pollution fields and foodstuff fields as well as medical fields.
Many devices and tools having an ion generator or an ion generating function to generate negative ions are used in homes, offices, plants, etc. The invention relates to air ion measuring devices, which are compact in construction and capable of accurately measuring the quantities of positive and negative ions contained in air in the above circumstances readily permitting the recognition of the results of measurements.
2. Prior Art
FIGS. 12 to 14 shows a prior art ion measuring device. The device comprises an ion detector 104, which has such a construction that it includes a cylindrical repelling electrode 102 provided on the inner surface of an air passage 101 formed in a cylindrical case 100 for withdrawing air formed in one end portion and exhausting the withdrawn air from the other end portion and a charge collector electrode 103 disposed at the center of the air passage 101. As an alternative construction, the ion detector 104 includes a pair of flat repelling electrodes 102 and a charge collector electrode 103 disposed mid way between the repelling electrodes 102. Reference numeral 105 designates posts for holding the charge collector electrodes 103.
Reference numeral 106 designates an air withdrawal fan, which is disposed in the other end portion of the air passage 101 opposing the air inlet in the afore-mentioned end portion in such orientation as to withdraw air in the same direction as the air passage direction. Reference numeral 107 designates a partitioning member, which is disposed at the outlet of the ion detector 104 and has a plurality of pores 108 for adjusting the air passage rate. Reference numeral 109 designates an air fitting, which constitutes a casing fitted on the repelling electrode or electrodes of the ion detector 104 provided on the surface of the air passage 101 and also on an air passage portion extending from the outlet of the ion detector 104 to the air withdrawal fan 106.
For measuring, for instance, negative ions in air with the above construction, air is passed through the air passage 101 by driving the air withdrawal fan 106 with the repelling electrode or electrodes 102 held negatively charged. In this way, negative ions in air passing by the repelling electrode or electrodes 102 are repelled to be more readily collected on the charge collector electrode 103, while positive ions are attracted to and neutralized by the negatively charged repelling electrode or electrodes 102. The charge collected on the charge collector electrode 103 is converted to voltage and measured. The measurement of positive ions may be made in like principles by positively charging the repelling electrode or electrodes.
In the prior art air ion measuring device having the above construction, however, the charge collector electrode is supported in a hanged state in the air passage at the center of the cylindrical repelling electrode or midway between the flat repelling electrodes. Inevitably, the thickness of the ion detector is correspondingly increased, and this dictates size increase of the measuring device itself. In addition, the number of components is increased by parts for holding the charge collector electrode, thus correspondingly dictating many steps of operation and much labor in manufacture. Furthermore, the structure itself constitutes a cause of cleaning difficulty. Furthermore, since the air withdrawal fan is oriented such as to withdraw air in the same direction as the air passage direction, it also constitutes a cause of thickness increase of the device itself.
Moreover, the disposition of the charge collector electrode as noted above does not only lead to an increase in the number of parts but also provides resistance offered to the air passage and causes disturbance thereof, which is undesired from the standpoint of accurate ion quantity measurement.
Likewise, the partitioning member for air passage rate adjustment, which is provided at the outlet of the ion detector, causes disturbance of air passage and is thus again undesired from the standpoint of accurate ion quantity measurement.
Still further, none of prior art portable air ion measuring devices could provide simultaneous display or graphic display of positive and negative ions. Also, none of prior air ion measuring devices could display relative humidity, temperature and atmospheric air pressure which may serve as important parameters for the quantity of air ions generated or could display date, time, etc.
The invention has an object of providing an air ion measuring device, which can solve all the above problems inherent in the prior art, can hold the air passage rate in an ion detector as constant as possible to improve the reliability of the air ion measurement while permitting reduction of its size and thickness and reduction of the ion detector parts cost, permits ready cleaning of the ion detector and is excellent in air ion data display, provides satisfactory coping with static electricity and good visual recognition property. According to the invention, this object is attained by an ion detector structure including an air passage, through which air is withdrawn from one end portion and exhausted from the other end portion, a charge collector electrode and repelling electrodes disposed in the neighborhood thereof, these electrodes being disposed on one side surface of the air passage, and a repelling electrode disposed on the other side surface of the air passage.